linux-stable.git/drivers/oprofile/cpu_buffer.c, branch linux-2.6.33.y

oprofile: remove double ring buffering

2010-07-05T18:15:30+00:00

commit cb6e943ccf19ab6d3189147e9d625a992e016084 upstream.

oprofile used a double buffer scheme for its cpu event buffer
to avoid races on reading with the old locked ring buffer.

But that is obsolete now with the new ring buffer, so simply
use a single buffer. This greatly simplifies the code and avoids
a lot of sample drops on large runs, especially with call graph.

Based on suggestions from Steven Rostedt

For stable kernels from v2.6.32, but not earlier.

Signed-off-by: Andi Kleen 
Cc: Steven Rostedt 
Signed-off-by: Robert Richter 
Signed-off-by: Greg Kroah-Hartman

percpu: make percpu symbols in oprofile unique

2009-10-29T13:34:13+00:00

This patch updates percpu related symbols in oprofile such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* drivers/oprofile/cpu_buffer.c: s/cpu_buffer/op_cpu_buffer/

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo 
Acked-by: Robert Richter 
Cc: Rusty Russell

x86/oprofile: introduce oprofile_add_data64()

2009-06-11T18:16:00+00:00

The IBS implemention writes 64 bit register values to the cpu buffer
by writing two 32 values using oprofile_add_data(). This patch
introduces oprofile_add_data64() to write a single 64 bit value to the
buffer.

Signed-off-by: Robert Richter

oprofile: remove obselete include headers

2009-06-11T14:10:12+00:00

This became obsolete with this commit:

 6dad828 oprofile: port to the new ring_buffer

Signed-off-by: Robert Richter

oprofile: fix cpu buffer size

2009-05-07T15:28:59+00:00

The unit of oprofile_cpu_buffer_size is in samples, but was allocated
in bytes. This led to the allocation of too small cpu buffers. This
patch recalculates the buffer size in bytes taking also the
ring_buffer_event header size into account.

Reported-by: Suravee Suthikulpanit 
Signed-off-by: Robert Richter

ring_buffer: remove unused flags parameter, fix

2009-02-06T00:14:05+00:00

Oprofile's ring-buffer use was not considered.

Signed-off-by: Ingo Molnar

oprofile: fix uninitialized use of struct op_entry

2009-01-17T16:26:39+00:00

Impact: fix crash

In case of losing samples struct op_entry could have been used
uninitialized causing e.g. a wrong preemption count or NULL pointer
access. This patch fixes this.

Signed-off-by: Robert Richter 
Signed-off-by: Ingo Molnar

oprofile: make new cpu buffer functions part of the api

2009-01-07T21:48:15+00:00

This patch creates the new functions

 oprofile_write_reserve()
 oprofile_add_data()
 oprofile_write_commit()

and makes them part of the oprofile api.

Signed-off-by: Robert Richter

oprofile: remove #ifdef CONFIG_OPROFILE_IBS in non-ibs code

2009-01-07T21:47:56+00:00

The ifdefs can be removed since the code is no longer ibs specific and
can be used for other purposes as well. IBS specific code is only in
op_model_amd.c.

Signed-off-by: Robert Richter

oprofile: use new data sample format for ibs

2009-01-07T21:47:23+00:00

The new ring buffer implementation allows the storage of samples with
different size. This patch implements the usage of the new sample
format to store ibs samples in the cpu buffer. Until now, writing to
the cpu buffer could lead to incomplete sampling sequences since IBS
samples were transfered in multiple samples. Due to a full buffer,
data could be lost at any time. This can't happen any more since the
complete data is reserved in advance and then stored in a single
sample.

Signed-off-by: Robert Richter